"Definitely it has given us cause for concern," said B. Gorman, spokesperson for the Tahoe Chamber. "I think that the lodging properties and restaurants are concerned and they are prepared for the fact they are going to have probably a slight decrease from what they had hoped for."

The Labor Day weekend is the last major holiday of the summer tourism season in Lake Tahoe.

Gorman said the chamber and many businesses have been flooded with phone calls from people with reservations trying to see if the smoke was clearing.

Some cancellations have been made, but many are waiting until the last minute to make a decision.

Many visitors aren't sacred away by the smoke, but it is impacting their plans.

"We actually were planning to go up on the gondola at Heavenly (Resort), and unfortunately with (the smoke) we have to change our plans," said Nick Issa, who is visiting Tahoe from the Bay Area.

"We're just staying indoors more, which is not the thing you want to do in Lake Tahoe," said Bonnie Sedlacek, who is visiting from Minnesota.

California Land Management, the state agency that oversees many of the campgrounds around Lake Tahoe, said reservations are down, about a third to a half of the normal crowds for the Labor Day weekend.